Uncovering an adaptive immune hallmark of extreme longevity.

Supercentenarians harbor expanded, nonexhausted CD4+ cytotoxic T lymphocytes that retain potent cytotoxicity and functional plasticity.

• Why it matters: Understanding immune features linked to extreme longevity can reveal mechanisms of healthy aging and resilience against age-related decline.
• What they did: Hashimoto et al. used single-cell profiling to identify these unique T cell populations in supercentenarians, highlighting their immune restructuring.
• The result: The presence of these cells suggests an adaptive immune system capable of managing persistent antigens, potentially contributing to the supercentenarians' exceptional healthy aging.